The invention relates to a control system for processing calls.
Many electronic devices are available for connection to a telephone line to provide automated voice and other functions. E.g., a voice response unit can be used to allow callers to enter touch tone digits in response to recorded prompts so as to direct the call to an appropriate class of answering agents. Typically these devices connect to telephone networks with ordinary analog connections or with T1 digital connections. Both of these interfaces provide limited flexibility for call control interaction with the network. In particular, transferring of calls, when possible at all, incurs the delay of switch hook manipulation and outdialing before transfer can take place.
Davidson et al. U.S. Pat. No. 5,062,103 describes a system in which the integrated services digital network (ISDN) shared call appearance feature is used so that a controller can obtain information from the switch as to whether an agent is busy or not so as to identify available agents to which calls can be forwarded for handling.